Jpn J Clin Oncol 2007;37(10)775 781 doi:10.1093/jjco/hym098 Current Status of Endocrine Therapy for Prostate Cancer in Japan Analysis of Primary Androgen Deprivation Therapy on the Basis of Data Collected by J-CaP Shiro Hinotsu 1, Hideyuki Akaza 1, Michiyuki Usami 2, Osamu Ogawa 3, Susumu Kagawa 4, Tadaichi Kitamura 5, Taiji Tsukamoto 6, Seiji Naito 7, Mikio Namiki 8, Yoshihiko Hirao 9, Masaru Murai 10, Hidetoshi Yamanaka 11 and The Japan Study Group of Prostate Cancer (J-CaP) 1 Urology and Andrology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 2 Department of Urology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, 3 Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 4 Tokushima University Hospital, Tokushima, 5 Department of Urology, Graduate School of Medicine, The University of Tokyo, Tokyo, 6 Department of Urology, Sapporo Medical University, School of Medicine, Sapporo, 7 Department of Urology, Graduate School of Medical Sciences, Kyushu University, Kyushu, 8 Department of Urology, Kanazawa University, School of Medicine, Kanazawa, 9 Department of Urology, Nara Medical University, Nara, 10 Department of Urology, School of Medicine, Keio University, Tokyo and 11 Institute for Preventive Medicine, Kurosawa Hospital, Kurosawa Received February 13, 2007; accepted June 8, 2007; published online October 26, 2007 Background: Based on the data of current status of endocrine therapy for prostate cancer registered in the Japan Study Group of Prostate Cancer (J-CaP), we conducted an analysis of primary androgen deprivation therapy (PADT) and an interim analysis of the prognosis. Methods: Ofthe26272casesregisteredintheserverofJ-CaP,the19409casesinitially receiving PADT were included in this study. The initial therapy was divided into eight categories according to its features. Results: Of the 19 409 patients, 1513 (7.8%) were given anti-androgen monotherapy, 955 patients (4.9%) surgical castration only, 1001 patients (5.2%) surgical castration þ anti-androgen, 3015 patients (15.5%) LHRH monotherapy, 1658 patients (8.5%) LH-RH þ short-term anti-androgen, 10 434 patients (53.8%) LH-RH þ anti-androgen, 37 patients (0.2%) watchful waiting and 796 patients (4.1%) other therapy. In progression-free survival, the prognosis was slightly better following maximum androgen blockade (MAB) in each stage. Conclusions: The pattern of PADT is more typical in Japan compared with that in the United States. Patients who received MAB accounted for 59.0% of all the patients. MAB tends to be more often selected for patients who are rated as being at high risk on the basis of high Gleason score or PSA level upon diagnosis in each clinical stage of the disease. Investigations of the outcome are on-going and they will make clear the significance of this trend in Japan. Key words: primary androgen deprivation therapy prostate cancer J-CaP INTRODUCTION Endocrine therapy for prostate cancer takes a more important position in Japan compared with in Europe and the United States (1). The Japan Study Group of Prostate Cancer (J-CaP) conducted an analysis of the registration status of the patients and their background variables as of October For reprints and all correspondence: Hideyuki Akaza, Urology and Andrology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba City, Ibaraki prefecture, 305-8575, Japan, E-mail: akazah@md.tsukuba.ac.jp 2003, and the result has been reported previously (2). The program completed the registration of the patients in 2004, and is performing a prognosis investigation. This analysis is revealing the current status of endocrine therapy for prostate cancer in Japan. PATIENTS AND METHODS J-CaP surveillance is a nationwide longitudinal observational study of patients newly starting hormone therapy for # 2007 Foundation for Promotion of Cancer Research
776 Hormonal therapy on prostate cancer prostate cancer from January 2001 to December 2003 (2). Institutions participating in this program registered individual cases, with entry of information pertaining to endocrine therapy via secure server over the Internet. After registration, information on the prognosis of individual registered cases and changes in treatment, if any, were entered periodically. As of 1 August 2006, 26 272 cases were registered in the J-CaP server. Of these cases, 26 170 cases were diagnosed by biopsy as having prostate cancer and began to receive treatment between 1 January 2001 and 31 December 2003. Among these cases, the number of cases who initially received primary androgen deprivation therapy (PADT) after diagnosis of prostate cancer and on whom detailed information on the endocrine therapy given was available was 19 409 (the year of starting treatment: 2001, 5921cases; 2002, 6424 cases; and 2003, 7064 cases). The present study analyzed these 19 409 cases for the type of PADT. DEFINITION OF INITIAL ENDOCRINE THERAPY Initial endocrine therapy was defined as follows. (1) Drugs used: Therapies using bicalutamide, flutamide, chrolmadinone acetate (CMA) or diethyl stilbestrol (DES) as anti-androgens. Therapies using 1-month or 3-month preparations of goserelin or lauprolide as LHRH agonists. (2) Timing of starting drug treatment; definition of initial therapy : In the patients receiving monotherapy with antiandrogen, or LH-RH agonist, or castration, if combined treatment with some other drug (anti-androgen or LH-RH agonist, or vice versa), started within 120 days, such combination therapy was deemed to be initial therapy. In cases where the drugs were added or modified for reasons of PSA failure, clinical failure, etc., the therapy given before the addition or modification was deemed to be initial therapy. In cases where some other drugs were added or the ongoing drug therapy was discontinued 120 days after the start of original treatment but earlier than the occurrence of failure, the original treatment given before the addition the drugs or discontinuation was deemed to be initial therapy. Anti-androgen therapy given during the period between 30 days before and 60 days after the start of LH-RH agonist therapy was defined as anti-androgen therapy for the purpose of flare prevention, and was classified as short-term anti-androgen therapy. (3) Watchful waiting: Patients reported as watchful waiting cases at the time of starting treatment were assigned to the category watchful waiting. (4) Others: Patients who received therapies other than bicalutamide, flutamide, CMA, DES, goserelin, leuprolide and surgical castration within 120 days after the start of treatment were assigned to the category others. In this way, initial therapy was divided into eight categories: (1) anti-androgen monothreapy; (2) surgical castration only; (3) LHRH agonist monotherapy; (4) LH-RH agonist þ short-term anti-androgen; (5) surgical castration þ anti-androgen; (6) LH-RH agonist þ anti-androgen; (7) watchful waiting; (8) other. The categories (3) and (6) are defined as maximal androgen blockade (MAB). The categories watchful waiting and others were excluded from part of this interim analysis of prognosis because the number of patients assigned to these two categories was too small. ANALYSIS OF PROGNOSIS Although the data are still immature for complete analysis, the interim analyses of prognosis on progression-free survival and overall survival were done. When calculating the progression-free survival, the first day of endocrine therapy was counted as the starting point. Events taken into account in calculation of the progression-free survival were PSA failure, clinical failure and death. If multiple events occurred in the same patient, the time of appearance of the first of these events was deemed as the time of event in this patient. In calculation of overall survival, the first day of endocrine therapy was counted as the starting point. Death (from cancer or other causes) was the event taken into account in calculation of overall survival, and the number of days until the event occurred was calculated. Cases where no event occurred were censored at the time of the final evaluation of the prognosis for both the progression-free survival and overall survival. Statistical analysis was performed using JMP5.1.2 (3). Trends of hormonal therapy were tested by chi-square test and the Cochran Mantel Haenszel test. Prognosis analyses were performed using Kaplan Meier methods. Survival analysis was tested by the log-rank test. Microsoft Excel was employed for depicting survival curves. RESULTS Of the 19 409 patients who initially received PADT after diagnosis of prostate cancer, 1513 patients (7.8%) were initially treated with anti-androgen monotherapy, 955 patients (4.9%) with surgical castration only, 3015 patients (15.5%) with LHRH monotherapy, 1658 patients (8.5%)
Jpn J Clin Oncol 2007;37(10) 777 with LHRH þ short-term anti-androgen, 1001 patients (5.2%) with surgical castration þ anti-androgen, 10 434 patients (53.8%) with LHRH þ anti-androgen, 37 patients (0.2%) with watchful waiting and 796 patients (4.1%) with other therapy (Fig. 1). Thus, 11 435 patients (59.0%) of all cases received MAB therapy. Table 1 shows the distribution type of institution, age at diagnosis, PSA at the time of diagnosis and Gleason score. Table 2 shows the distribution of T category, N category, M category (according to UICC, TNM Classification of the Malignant Tumors, 5th edn (4)) and clinical stage. When analyzed by T category (Fig. 2), the percentage of cases receiving LHRH agonist þ anti-androgen or surgical castration þ anti-androgen rose as the T category advanced (P, 0.0001). A similar trend was also noted as the clinical stage (rated on the basis of not only T category but also N and M categories) advanced (P, 0.0001; Fig. 2). When the endocrine therapy for T1-T2N0M0 cases was analyzed in relation to risk category according to the classification of D Amico et al. (5) (Fig. 2), the percentage of cases treated with LHRH þ antiandrogen or castration þ anti-androgen (MAB) increased as the risk became higher (P, 0.0001). When the relationship between the age at the time of diagnosis and endocrine therapy was analyzed for each clinical stage (Fig. 3), the percentage of cases receiving MAB tended to decrease slightly as the age became higher, irrespective of the clinical stage. Among patients over 80 years of age, the percentage of cases receiving surgical castration tended to rise slightly. According to a previously reported study in the United States on the selection of endocrine therapy for prostate cancer, treatment of localized prostate cancer with LHRH agonists was often selected for patients over 80 years of age irrespective of disease stage and histological features (6). Therefore, although direct comparison between Japan and the United States is not possible, there seems to be some differences in the selection of therapy for Figure 1. Initial endocrine therapy. AA, anti-androgen monotherapy; SC, surgical castration only; SC þ AA, surgical castration þ anti-androgen; LHRH, LH-RH agonist monotherapy; LHRH þ shortaa, LH-RH agonist þ short-term anti- androgen; LHRH þ AA, LH-RH agonist þ anti-androgen; WW, watchful waiting. prostate cancer between the two countries. When the relationship between PSA level at the time of diagnosis and endocrine therapy was analyzed for each clinical stage of prostate cancer (Fig. 4), the percentage of cases treated with LHRH agonist þ anti-androgen or surgical castration þ anti-androgen tended to be higher in cases with PSA over 20, irrespective of disease stage (P, 0.05 in all stages). Also in the analysis in relation to Gleason score (Fig. 5), the percentage of cases treated with LHRH agonist þ antiandrogen or surgical castration þ anti-androgen became higher as the Gleason score rose irrespective of clinical stage of the disease in the cases with Gleason score of 5 or more (P, 0.001 in stages II and III). Combined together, these results indicate that patients with high risk (rated on the basis of PSA level at the time of diagnosis and Gleason Table 1. The distribution of type of institution, age at the diagnosis, PSA at the time of diagnosis and Gleason score at the time of diagnosis by year of registration 2001 2002 2003 Total % Type of institution University Hospital 1180 1221 1185 3586 18.5 Public Hospital 4179 4501 5139 13819 71.2 Private Hospital 562 702 740 2004 10.3 Age at Diagnosis,60 171 183 164 518 2.7 60 64 334 381 410 1125 5.8 65 70 713 776 822 2311 11.9 70 74 1476 1578 1757 4811 24.8 75 79 1625 1831 2124 5580 28.7 80 1602 1675 1787 5064 26.1 PSA at Diagnosis 0 4 220 243 258 721 3.7 4 10 1108 1340 1620 4068 21.0 10 20 1050 1223 1454 3727 19.2.20 3532 3607 3718 10857 55.9 No description 11 11 14 36 0.2 Gleason score 2 4 502 407 415 1324 6.8 5 6 1262 1506 1832 4600 23.7 7 1246 1634 1967 4847 25.0 8 10 1541 2139 2421 6101 31.4 No description 1370 738 429 2537 13.1 PSA, prostate specific antigen.
778 Hormonal therapy on prostate cancer Table 2. The distribution of T category, N category, M category and clinical stage by year of registration 2001 2002 2003 Total % T stage T1a,b 193 171 133 497 2.6 T1c 946 1122 1455 3523 18.2 T2a 912 1047 1198 3157 16.3 T2b 900 1009 1222 3131 16.1 T3 2302 2352 2399 7053 36.3 T4 636 687 621 1944 10.0 No description 32 36 36 104 0.5 N factor N0 4507 4982 5717 15206 78.3 N1 969 977 929 2875 14.8 NX 413 429 382 1224 6.3 No description 32 36 36 104 0.5 M factor M0 3829 4303 5112 13244 68.2 M1 145 128 92 365 1.9 M1a 78 81 67 226 1.2 M1b 1504 1546 1367 4417 22.8 M1c 99 76 105 280 1.4 Mx 234 254 285 773 4.0 No description 32 36 36 104 0.5 Clinical Stage II 2370 2719 3390 8479 43.7 III 998 1088 1215 3301 17.0 IV 2043 2079 1905 6027 31.1 No description 510 538 554 1602 8.3 Figure 2. Initial endocrine therapy trends according to T category, clinical stage and D Amico s risk classification. (Abbreviations as in Fig. 1.) Figure 3. Initial endocrine therapy according to age in clinical stages II, III and IV. (Abbreviations as in Fig. 1.) score) at each clinical stage of disease were more frequently treated with MAB therapy rather than LH-RH agonist or anti-androgen monotherapy. An interim analysis on the prognosis was performed using the data on 19 327 cases on whom prognosis data were available for at least one point of evaluation. The number of events was 5723 and the median follow-up period was 1441 days in the progression-free survival analysis. In the overall survival analysis, the number of events was 2330. Data on prognosis was best following treatment with castration þ anti-androgen for stage II cases, and was best following treatment with castration þ anti-androgen or LHRH agonist þ anti-androgen for stage III cases in the Figure 4. Initial endocrine therapy according to PSA level at the time of diagnosis in clinical stages II, III and IV. (Abbreviations as in Fig. 1.) period until about 3 years after the start of treatment in progression-free survival (Fig. 6). As described above, MAB therapy tends to be selected more frequently for high-risk
Jpn J Clin Oncol 2007;37(10) 779 Figure 5. Initial endocrine therapy according to Gleason score at the time of diagnosis in clinical stages II, III and IV. (Abbreviations as in Fig. 1.) patients at each clinical stage of the disease, but in stage II and III cases, MAB therapy exerts an efficacy which is high enough to offset the influence of background variables (P, 0.0001, log-rank test, MAB vs not MAB). In stage IV cases, no evident difference in prognosis was noted among different methods of endocrine therapy. In the overall survival, the prognosis was slightly better following MAB therapy in stage III (P ¼ 0.006) and stage IV cases (P ¼ 0.001), but the number of events was too small to allow any definite conclusion, and further prognosis investigation is needed (Fig. 7). DISCUSSION J-CaP surveillance was started to investigate the current status of endocrine therapy for prostate cancer in Japan by collecting data on many cases of prostate cancer registered across Japan (2). The data collected in this program reflect the current status of the clinical practice on adoption and modification of the strategy for treatment of prostate cancer in Japan based on the therapeutic policy at individual medical facilities. The Japanese Urological Association (JUA) strongly recommends that diagnosing prostate cancer and taking records of its diagnosis should be based on the General Rule for Clinical and Pathological Studies on Prostate Cancer (7). Therefore, there seems to be little difference in the method of diagnosis and records of prostate cancer among different facilities. As shown in Table 1, 18.5% of all cases analyzed were patients treated at university hospitals. This distribution of data in this study differs from that in CaPSURE in which 9.1% of all cases were registered at academic institutions (8). We may therefore say that the cases analyzed in this study reflect the current status of treatment of prostate cancer throughout Japan, including cases treated at academic institutions as well. The present study was a survey of the actual state of treatment and not a randomized comparison within an experimental frame. The survey revealed that, when a method of treatment was selected, various background variables were Figure 6. Progression-free survival in (a) clinical stage II, (b) clinical stage III and (c) clinical stage IV. (Abbreviations as in Fig. 1.) taken into account, and MAB therapy tended to be often selected for high-risk patients, as stated above. It is difficult, therefore, to make any conclusion about responses to endocrine therapy corrected for the influence from background variables. To our knowledge, no previous study has analyzed data from so many cases registered from a given district as in the present study. No previous report examined so detailed a characterization of individual methods of treatment and dealt with analysis of endocrine therapy divided into such small categories as in the present study. If the data collected by this study group are summarized, we may say that MAB therapy is possibly superior in terms of progression-free
780 Hormonal therapy on prostate cancer Figure 7. Overall survival in (a) clinical stage II, (b) clinical stage III and (c) clinical stage IV. (Abbreviations as in Fig. 1.) survival for stage II and III cases and overall survival for stage IV cases. The Guidelines on Diagnosis and Treatment of Prostate Cancer, edited by JUA, and published in May 2006 (9), also quote the results of Japanese randomized controlled trials, suggesting the effectiveness of endocrine therapy alone for localized prostate cancer (10). Endocrine therapy has been often selected for the treatment of localized prostate cancer relatively extensively in Japan. Accumulation of data on outcomes of this kind of treatment will facilitate review of the clinical stages of prostate cancer indicated for endocrine therapy (1). When such a review is made, the usefulness of MAB needs to be evaluated on the basis of a general assessment of efficacy, adverse events, QOL and economic aspects. J-CaP now plans to conduct a survey of adverse events, with a goal of evaluating the efficacy of endocrine therapy for prostate cancer in more detail while taking into account adverse events and QOL. J-CaP also plans to conduct a further long-term prognosis survey and an investigation of cause of death of the patients who died. If the data from these surveys are collected and analyzed, it will be possible for us to make more detailed reports on the advantages and disadvantages of endocrine therapy alone, not only for advanced prostate cancer but also for localized prostate cancer. At that time, we must discuss the economic aspect of how long the endocrine therapy should be continued. The role played by endocrine therapy for localized prostate cancer in Japan differs markedly from that in Europe and the United States. According to the prostate registry operated by JUA (11), which included 4529 registered patients who were diagnosed with prostate cancer in 2000, PADT was selected as an initial treatment for 45.9% of the 2671 patients with stage T1c-T3N0M0 prostate cancer. In the United States, the number of cases with localized prostate cancer treated with PADT has also been increasing, according to the CaPSURE report and the SEER data, but the number in the United States is less than half of that in Japan (6,8). A recent analysis made by CaPSURE yielded a noteworthy finding as to the background variables of patients for whom PADT was selected (12). In the existing guidelines pertaining to the treatment of localized prostate cancer, especially in the United States, there is hardly any statement that recommends the use of PADT. This may be explained by the following factors: (1) PADT is viewed only as a means of conservative treatment of advanced cancer; and (2) there is concern over androgen deprivation syndrome appearing as an adverse reaction to PADT (1). In Europe and the United States, few high-quality clinical studies have been carried out on PADT used for the treatment of localized prostate cancer, and clinical evidence is absent. Then, why has the use of PADT for the treatment of localized prostate cancer been increasing in the United States in recent years? Shahinian et al. viewed selection of PADT as a Wennberg s practice style hypothesis and explained that it is primarily dependent on the view of individual urologists (13). A Wennberg s hypothesis is that, when there is uncertainty about the optimal treatment course, use of medical interventions is determined by the characteristics of the physician. In other words, the treatment provided depends more on the physician who is treating the patient than on specific characteristics of the patient s disease. However, the analysis made by Kawakami et al., cited above, involved a comparison between radical therapy and palliative therapy and suggested that the selection of PADT was based on the relatively evident features of patient s background and the results of recent clinical studies demonstrating the efficacy of this
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